Within the finite-density QCD sum-rule approach we investigate the self-energies of Σ hyperons propagating in nuclear matter from a correlator of Σ interpolating fields evaluated in the nuclear matter ground state. We find that the Lorentz vector self-energy of the Σ is similar to the nucleon vector self-energy. The magnitude of Lorentz scalar self-energy of the Σ is also close to the corresponding value for nucleon; however, this prediction is sensitive to the strangeness content of the nucleon and to the assumed density dependence of certain four-quark condensate. The scalar and vector self-energies tend to cancel, but not completely. The implications for the couplings of Σ to the scalar and vector mesons in nuclear matter and for the Σ spin-orbit force in a finite nucleus are discussed.

• Received 18 May 1994

DOI:https://doi.org/10.1103/PhysRevC.51.347